Dude! I think I had it all wrong. I believe that when MIB went into the waterfall of light the smoke monster was already there. I think what we have been seeing all of this time is not really Jacob's brother, but an ACTUAL LIVING evil that has been waiting for someone to set it free. Jacob's brother is dead they conned us into believing he was the bad guy when in actuallity, his bro is dead and it is basically Jacob vs. a smoke monster, not his brother. Just a theory, but I think that I have something.